Local area networks (LANs), which were once merely a desirable technology available to share common network resources, are now an integral part of any information technology (IT) infrastructure. Moreover, the concept of the LAN has expanded to the wide area network (WAN), where remote offices and databases are made available to LAN clients as through they are connected to the same LAN. More recently, virtual private networks (VPN) have been utilized to allow a private intranet to be securely extended across the Internet or other network service, facilitating secure e-commerce and extranet connections with partners, suppliers and customers. The evolution of global networking has rapidly advanced networking topologies.
LAN segments are routinely connected together using a bridge device. The bridge device allowed the two network segments to share traffic despite differences in the network topologies. For Example, a Token Ring network and an Ethernet network can share network traffic using a bridge device.
Routers became popular to couple one LAN to another LAN or WAN. Routers store data packets from one LAN and forward those data packets to another LAN or WAN. The need for faster communication resulted in the development of the high-speed switch, also referred to as a layer ⅔ switch. High-speed switches move data packets across a network to an end user.
When client-server networks first emerged, servers were generally placed close to their clients. As the applications delivered over networks became more advanced, the servers increased in complexity and capacity. Moreover, applications that ran over these networks such as e-mail, intranet web sites, and Internet gateways, became indispensably pervasive. Supporting these services became critically important, and proved far too complex when servers were widely distributed within the enterprise. As a result, it has become a standard practice to consolidate such resources into server arrays.
A Server array controller is an Internet traffic management device. Server array controllers (hereinafter referred to simply a “controller” or “controllers”) control the flow of data packets in and out of an array of application servers. The controller manages and distributes Internet, intranet and other user requests across redundant arrays of network servers, regardless of the platform type. Controllers support a wide variety of network applications such as web browsing, e-mail, telephony, streaming multimedia and other Internet protocol (IP) traffic.
Although advances in data communication technology have dramatically improved the transmission speeds, many problems still exist. Application availability can still be threatened by content failure, software failure or server failure. System resources are often out of balance, with low-performance resources receiving more user requests than high-performance resources being underutilized. Internet Traffic Management (ITM) products are computer systems that sit in the network and process network traffic streams. ITM products switch and otherwise respond to incoming requests by directing them to one of the servers.
A more complete appreciation of the invention and its improvements can be obtained by reference to the accompanying drawings, which are briefly summarized below, to the following detail description of presently preferred embodiments of the invention, and to the appended claims.